Copepoda (Crustacea) from fresh waters of the Florida Everglades, U.S.A., with a description of Eucyclops conrowae n. sp.

Abstract

This first collection of Copepoda (Crustacea) from fresh waters in the Florida Everglades yielded 13 species: the calanoid Osphranticum labronectum, the cyclopoids Acanthocyclops robustus, Eucyclops bondi, Macrocyclops albidus, Mesocyclops americanus, Microcyclops rubellus, Microcyclops varicans, and Tropocyclops prasinus mexicanus, the harpacticoids Cletocamptus deitersi, Onychocamptus mohammed, and Phyllognathopus viguieri, and two previously unknown species: Thermocyclops parvus, described elsewhere, and Eucyclops conrowae, n. sp., described herein. Eucyclops conrowae is distinguished principally by the posteriorly produced pedigers 2-4, caudal rami 3.5 times longer than broad, median terminal caudal setae with short coarse spiniform setules, antennule reaching posterior margin of pediger 2, leg 4 exopodite article 3 with some setae flanged, and leg 4 endopodite article 3 with lateral and distomedial setae short, sclerotized, and blunt. The neotropical species E. bondi is newly recorded for the United States. Specimens of M. albidus resemble tropical rather than European populations in having short caudal rami. As a result of this collection and additional material examined, the known range of M. americanus is extended from Ontario south to Florida and west to Indiana. The previously unknown male of M. americanus is described from specimens collected in the Everglades. The ornamentation of the anal somite and the relative lengths of the leg 4 endopodite article 2 terminal spines distinguished populations ascribed to M. rubellus and M. varicans. The Everglades copepods, collected from a shallow slough, have few species in common with assemblages reported from mainly planktonic collections in central Florida. Especially diaptomid calanoids, common in central and northern Florida, were absent from the Everglades collection. The freshwater copepod crustacean fauna, especially the planktonic species, of central Florida has become well known from numerous reports (Bays & Crisman, 1983; Cowell et al., 1975; Elmore et al., 1984; and others). However, the freshwater copepods of the Florida Everglades are almost completely uninvestigated. To my knowledge, the only previous collection from the area was made by Davis (1948) from Long Lake, a small brackish-water lake (salinity 15.39%o, as measured by Davis) near the south end of Everglades National Park (Fig. 1). Davis reported three species, all since synonymized with other taxa: Pseudodiaptomus coronatus Williams, 1906 (=P. pelagicus Herrick, 1884), 1 I thank Dr. Hans-Walter Mittmann for arranging the loan of specimens from the Friedrich Kiefer Copepod Collection at the Staatliches Museum fur Naturkunde Karlsruhe, Germany. Dr. Richard L. Whitman allowed me to examine his collection of cyclopoid copepods from the Indiana Dunes National Lakeshore, and Ms. Dorinda Partsch authorized the long-term loan of a specimen from this collection to the National Museum of Natural History. Dr. Bruce C. Cowell kindly made me aware of additional references. Comments by Dr. Eugene H. Schmitz and two anonymous reviewers improved the text. Publication costs, in part, are being met by a grant from the SpencerTolles Fund of the American Microscopical Society. TRANS. AM. MICROSC. SOC., 111(3): 229-254. 1992. ? Copyright, 1992, by the American Microscopical Society, Inc. This content downloaded from 157.55.39.105 on Fri, 07 Oct 2016 04:21:25 UTC All use subject to http://about.jstor.org/terms TRANS. AM. MICROSC. SOC. Acartia floridana Davis, 1948 (=A. tonsa Dana, 1852), and Cyclops panamensis var. tannica Davis, 1948 (=Apocyclops panamensis (Marsh, 1913)). All of these are typical inhabitants of coastal brackish waters. Ms. Roxanne Conrow, formerly of the South Florida Research Center, Everglades National Park, confided to me for determination three samples of planktonic Copepoda taken from a shallow freshwater slough. These samples proved to contain 13 species of Copepoda, including two species new to science. One of these species is described herein, as is the previously unknown male of Mesocyclops americanus Dussart, 1985. Another, Thermocyclops parvus, was described elsewhere (Reid, 1989). The known distributions of several species were extended considerably by this collection. In the case of M. americanus, examination of additional specimens lent by the Staatliches Museum fur Naturkunde Karlsruhe and by the Indiana Dunes National Lakeshore resulted in other new records, also listed herein. MATERIALS AND METHODS The qualitative samples were taken with a plankton net in Shark River Slough, within and just outside Everglades National Park (Fig. 1). Sample 1 was consolidated from collections made at several locations in the slough on different dates in 1986. Collection data for the remaining two samples were supplied by R. Conrow: site 6 (25?37.2'N, 80?43.9'W), collected in April 1986, is in the central part of the slough, and site 23 (25?40.0'N, 80?36.9'W), collected in May 1986, in the northeastern part. Water depths were 14-23 cm at site 6 and 1429 cm at site 23. At site 6, the substrate is predominantly peat, but at site 23 it is marl. Additional ambient data are not available for these sites on these dates. Loftus & Kushlan (1987) provided a detailed characterization of Everglades waters, from which the following data are summarized: pH varies from 7.0 to 8.5, specific conductance from 400 to 700 utSiemens cm-1 during dry periods when concentrations of most major ions increase, and dissolved oxygen from 0.7 to 14.2 ppm, with marked diurnal fluctuation being the rule. Turbidity and color values, as well as nutrient levels, are low during much of the year, but they increase during the dry season. Specimens were fixed in buffered 5% formalin and later transferred to 70% ethanol for long-term storage. For taxonomic determination, individual specimens were transferred to a solution of 70% ethanol-10% glycerin that was allowed to evaporate to nearly pure glycerin. Specimens were examined before dissection in glycerin or in lactic acid. Measurements were made of specimens in glycerin by means of an ocular micrometer. Permanent mounts of some were made in commercial polyvinyl lactophenol medium with a little chlorazol black E added. Drawings were made at magnifications of 400 x or 600 x using a Wild M50 compound microscope fitted with a camera lucida. Details of some structures were confirmed using an oil immersion lens at 1,000 x. Specimens were deposited either in the collections of the National Museum of Natural History, Smithsonian Institution (USNM), or at the South Florida Research Center, Everglades National Park (SFRC). 230 This content downloaded from 157.55.39.105 on Fri, 07 Oct 2016 04:21:25 UTC All use subject to http://about.jstor.org/terms VOL. 111, NO. 3, JULY 1992 FIG. 1. The southern tip of the state of Florida, U.S.A., showing the locations of sample sites 6 and 23. The heavy dashed line indicates the boundaries of Everglades National Park; the light dashed line shows the approximate boundaries of Shark River Slough.